Electronic device and method for manufacturing same

ABSTRACT

An electronic device includes: a support member that has a metallic placement surface joined to the conductive bonding layer, and a metallic sealing surface provided on an outer side of the placement surface in an in-plane direction of the placement surface to adjoin the placement surface and to surround the placement surface; and a resin member, which is a synthetic resin molded article, joined to the sealing surface and covering the electronic component. The sealing surface includes a rough surface having a plurality of laser irradiation marks having a substantially circular shape. The rough surface includes a first region and a second region. The second region has a higher density of the laser irradiation marks in the in-plane direction than the first region.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application of InternationalPatent Application No. PCT/JP2017/028285 filed on Aug. 3, 2017, whichdesignated the U.S. and claims the benefit of priority from JapanesePatent Application No. 2016-204479 filed on Oct. 18, 2016 and JapanesePatent Application No. 2016-204480 filed on Oct. 18, 2016. The entiredisclosures of all of the above applications are incorporated herein byreference.

TECHNICAL FIELD

The present disclosure relates to an electronic device and a method formanufacturing the electronic device.

BACKGROUND

A semiconductor device, which has a structure with an electroniccomponent (e.g., an IC chip) bonded to a metal surface and a resinmember in tight contact with the metal surface, is subjected toimprovement.

SUMMARY

The present disclosure describes an electronic device mounted with anelectronic component and a method for manufacturing the electronicdevice.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a cross-sectional view illustrating a schematic configurationof an electronic device of a first embodiment.

FIG. 2 is a plan view of the electronic device shown in FIG. 1.

FIG. 3 is a plan view of a support member shown in FIG. 1.

FIG. 4A is a partially enlarged cross-sectional view of the supportmember shown in FIG. 1.

FIG. 4B is a partially enlarged cross-sectional view of the supportmember shown in FIG. 1.

FIG. 5 is a partially enlarged cross-sectional view of the supportmember in a manufacturing step of the electronic device shown in FIG. 1.

FIG. 6 is a plan view of the support member in a manufacturing step ofthe electronic device shown in FIG. 1.

FIG. 7 is a plan view illustrating a schematic configuration of avariation example of the electronic device of the first embodiment,

FIG. 8 is a plan view of the support member in a manufacturing step ofthe electronic device shown in FIG. 7.

FIG. 9 is a plan view illustrating a schematic configuration of anothervariation example of the electronic device of the first embodiment.

FIG. 10 is a plan view illustrating a schematic configuration of yetanother variation example of the electronic device of the firstembodiment.

FIG. 11 is a cross-sectional view illustrating a schematic configurationof an electronic device of a second embodiment.

FIG. 12 is a plan view of the electronic device shown in FIG. 11.

FIG. 13 is a plan view of a support member shown in FIG. 11.

FIG. 14 is a partially enlarged cross-sectional view of the supportmember shown in FIG. 11,

FIG. 15 is a partially enlarged cross-sectional view of the supportmember in a manufacturing step of the electronic device shown in FIG.11,

FIG. 16 is a partially enlarged cross-sectional view of the supportmember in a manufacturing step of the electronic device shown in FIG.11.

FIG. 17 is a partially enlarged cross-sectional view of the supportmember in a manufacturing step of the electronic device shown in FIG.11.

FIG. 18 is a partially enlarged cross-sectional view of the supportmember in a manufacturing step of the electronic device shown in FIG.11.

FIG. 19 is a partially enlarged cross-sectional view of the supportmember and others in a manufacturing step of the electronic device shownin FIG. 11,

FIG. 20 is a partially enlarged cross-sectional view of the supportmember and others in a manufacturing step of the electronic device shownin FIG. 11.

FIG. 21 is a partially enlarged cross-sectional view of the electronicdevice in a manufacturing step of the electronic device shown in FIG.11.

FIG. 22 is a partially enlarged cross-sectional view of the supportmember in a manufacturing step of a variation example of the electronicdevice of the second embodiment.

FIG. 23 is a plan view of the support member in the manufacturing stepof the variation example of the electronic device.

FIG. 24 is a partially enlarged cross-sectional view of the supportmember and others in the manufacturing step of the variation example ofthe electronic device.

FIG. 25 is a plan view illustrating a schematic configuration of anothervariation example of the electronic device of the second embodiment.

FIG. 26 is a plan view illustrating a schematic configuration of yetanother variation example of the electronic device of the secondembodiment.

FIG. 27 is a plan view illustrating a schematic configuration of yetanother variation example of the electronic device of the secondembodiment.

FIG. 28 is a plan view illustrating a schematic configuration of yetanother variation example of the electronic device of the secondembodiment.

DETAILED DESCRIPTION

A technique for making a metal surface rough by laser beam irradiationto enhance bonding between a resin member and a metal surface in asemiconductor device is subjected to improvement. Thus, a furtherimprovement in the bonding between the metal surface and the resinmember has been demanded.

In an electronic device according to a first aspect of the presentdisclosure, an electronic component is mounted through a conductivebonding layer. The electronic device includes; a support member having ametallic placement surface joined to the conductive bonding layer, and ametallic sealing surface provided on an outer side of the placementsurface in an in-plane direction of the placement surface to adjoin theplacement surface and to surround the placement surface; and a resinmember, which is a synthetic resin molded article, joined to the sealingsurface and covering the electronic component. The sealing surfaceincludes a rough surface having a plurality of laser irradiation markshaving a substantially circular shape. The rough surface includes afirst region and a second region, which has a higher density of thelaser irradiation marks in the in-plane direction than the first region.The second region is provided correspondingly to a desirable portion,for example, a portion of a joint between the support member and theconductive bonding layer or between the support member and the resinmember where internal stress is higher than in other portions of thejoint. Therefore, the bonding between the resin member and the metallicsealing surface at the support member is further improved.

In an electronic device according to a second aspect of the presentdisclosure, an electronic component is mounted through a conductivebonding layer. The electronic device includes: a support member thatincludes a metallic placement surface joined to the conductive bondinglayer, and a metallic sealing surface provided on an outer side of theplacement surface in an in-plane direction of the placement surface toadjoin the placement surface and to surround the placement surface; anda resin member that is a synthetic resin molded article joined to thesealing surface and covering the electronic component.

In the above-mentioned configuration, the rough surface with the laserirradiation marks is formed on the sealing surface of the supportmember. The rough surface is provided correspondingly to a portion of ajoint between the support member and the conductive bonding layer orbetween the support member and the resin member. Internal stress ishigher at the portion of the joint than in other portions of the joint.Therefore, the bonding between the resin member and the metallic sealingsurface at the support member is further improved.

A manufacturing method related to a third aspect of the presentdisclosure is a method for manufacturing an electronic device in whichan electronic component is mounted through a conductive bonding layer.

The manufacturing method related to the third aspect of the presentdisclosure includes: forming a metallic sealing surface by irradiating,with a pulsed laser beam, a portion of one planar metal surface of asupport member; mounting the electronic component on the support memberthrough the conductive bonding layer by joining the conductive bondinglayer to a placement surface that includes the non-laser-irradiatedregion; and covering the electronic component with a resin member, whichis a synthetic resin molded article, by joining the resin member to thesealing surface. The sealing surface is formed on an outer side of anon-laser-irradiated region of the planar metal surface in an in-planedirection of the planar metal surface, the non-laser-irradiated regionbeing closer to a central portion of the planar metal surface in thein-plane direction. The sealing surface includes a rough surface havinga plurality of laser irradiation marks having a substantially circularshape, while the non-laser-irradiated region is free of the laserirradiation marks. The rough surface includes a first region and asecond region, the second region having a higher density of the laserirradiation marks in the in-plane direction than the first region.

An electronic device can be manufactured with the manufacturing methodrelated to the third aspect in an improving manner.

A manufacturing method related to a fourth aspect of the presentdisclosure is a method for manufacturing an electronic device in whichan electronic component is mounted through a conductive bonding layer.The manufacturing method includes; forming a metallic sealing surface byirradiating, with a pulsed laser beam, a portion of one planar metalsurface of a support member; mounting the electronic component on thesupport member through the conductive bonding layer by joining theconductive bonding layer to a placement surface that includes thenon-laser-irradiated region; and covering the electronic component witha resin member, which is a synthetic resin molded article, by joiningthe resin member to the rough surface. The sealing surface is formed onan outer side of a non-laser-irradiated region of the planar metalsurface in an in-plane direction of the planar metal surface, thenon-laser-irradiated region being closer to a central portion of theplanar metal surface in the in-plane direction. The sealing surfaceincludes a rough surface having a plurality of laser irradiation markshaving a substantially circular shape, while the non-laser-irradiatedregion is free of the laser irradiation marks. The sealing surface isformed at a position corresponding to a portion of a joint between thesupport member and the conductive bonding layer or between the supportmember and the resin member, and internal stress is higher at theportion of the joint with the sealing surface than in other portions ofthe joint.

An electronic device can be manufactured with the manufacturing methodrelated to the fourth aspect in an improving manner.

In an electronic device according to a fifth aspect of the presentdisclosure, an electronic component is mounted through a conductivebonding layer. The electronic device includes; a support member having ametallic placement surface joined to the conductive bonding layer, and ametallic sealing surface provided on an outer side of the placementsurface in an in-plane direction of the placement surface to adjoin theplacement surface and to surround the placement surface; and a resinmember, which is a synthetic resin molded article, joined to the sealingsurface and covering the electronic component. The sealing surfaceincludes a rough surface provided with a plurality of laser irradiationmarks each having a substantially circular shape. A boundary area, whichis a portion of the placement surface adjoining the sealing surface inthe in-plane direction, has an improved wettability for a materialproviding the conductive bonding layer than the rough surface of thesealing surface.

A manufacturing method according to a sixth aspect of the presentdisclosure is a method for manufacturing an electronic device in whichan electronic component is mounted through a conductive bonding layer.The method includes: forming a metallic sealing surface by irradiating,with a pulsed laser beam as a surface roughening beam, a portion of oneplanar metal surface of a support member; forming a metallic placementsurface on the support member by irradiating a boundary area with apost-processing laser beam such that wettability for a material formingthe conductive bonding layer is improved in the boundary area than onthe rough surface of the sealing surface; mounting the electroniccomponent on the support member through the conductive bonding layer byjoining the conductive bonding layer to the placement surface; andcovering the electronic component with a resin member being a syntheticresin molded article by joining the resin member to the sealing surface.The sealing surface is formed on an outer side of a non-laser-irradiatedregion of the planar metal surface in an in-plane direction of theplanar metal surface, the non-laser-irradiated region being closer to acentral portion of the planar metal surface in the in-plane direction.The sealing surface includes a rough surface having a plurality of laserirradiation marks having a substantially circular shape, while thenon-laser-irradiated region is free of the laser irradiation marks. Theplacement surface is to be joined to the conductive bonding layer, andincludes the boundary area and the non-laser-irradiated region. Theboundary area includes an outer edge of the non-laser-irradiated region.The post-processing laser beam has a lower energy level than the surfaceroughening beam.

With regard to the above configurations and the manufacturing methods,the rough surface having the laser irradiation marks is formed byirradiating the support member with the surface roughen beam. Therefore,the bonding between the resin member and the metallic sealing surface ofthe support member is further improved. On the other hand, thenon-irradiated region of the support member near the central part in thein-plane direction is formed. That is, the sealing surface is formed onthe outer side of the non-irradiated region in the in-plane direction.

At this time, deposits accumulate inside and around the laserirradiation marks. The deposits are composed of substances such as themetal that forms the support member and/or compounds and the like (e.g.,oxides) of the metal. Accumulation and the like of these deposits createminute irregularities inside and around the laser irradiation marks.

The accumulation of deposits and/or concurrent formation of minuteirregularities can also occur in the boundary area that adjoins thesealing surface in the in-plane direction of the placement surface. Ifthis happens, there is a risk that wettability of the material formingthe conductive bonding layer may be deteriorated in the boundary areadue to the influence of the compounds and the like mentioned above.

According to the structure and manufacturing method described above, theboundary area is irradiated with the post-processing beam that is alaser beam with a lower energy level than that of the surface rougheningbeam. The irradiation with the post-processing beam favorably removesthe compounds and the like mentioned above, which are one cause ofdeterioration of the wettability. Thus, the wettability is made morefavorable in the boundary area than on the rough surface of the sealingsurface. Therefore, a good bond with the conductive bonding layer on theplacement surface can be secured, while a favorable bond is alsorealized between the sealing surface and the resin member.

The embodiments will be described with reference to the drawings below.Parts identical or equivalent to each other in various embodiments andvariation examples thereof that are described later are given the samereference numerals. Where applicable, descriptions of previousembodiments can be referred to as required to the embodiments orvariations examples that follow, unless there are technicalcontradictions or otherwise additionally described.

Structure of First Embodiment

The configuration of an electronic device 1 of the present embodimentwill be described with reference to FIG. 1 to FIG. 3, FIG. 4A, and FIG.4B. As shown in FIG. 1, the electronic device 1 includes a supportmember 2, an electronic component 3, a conductive bonding layer 4, and aresin member 5. For convenience of illustration and description, agraphic indication and presentation of detailed features such as aprotective film, wiring, and the like with which the electronic device 1is commonly provided are omitted in each drawing. For the same reasons,the resin member 5 is not shown in the plan view of FIG. 2.

The support member 2 is a component that supports the electroniccomponent 3, and formed as a metal member in the present embodiment.More specifically, the support member 2 is a component known as a leadframe and formed in a flat plate shape at least in a section bonded tothe electronic component 3 and in its vicinity. The structure of thesupport member 2 will be described in detail later. In the presentembodiment, the electronic component 3 is an IC chip, and has a planarshape that is rectangular as shown in FIG. 2. The “planar shape” hererefers to the shape of one of a pair of main surfaces that are the pairof surfaces with the largest area of the electronic component 3 formedin a hexahedron shape, viewed from a direction parallel to the normal ofthe one of the main surfaces. The “planar shape” may also refer to ashape as viewed in plan, i.e., a shape in a plan view.

The conductive bonding layer 4 is a component for bonding the electroniccomponent 3 on a mounting surface 20 that is one surface of the supportmember 2, and composed of solder or conductive adhesive. An in-planedirection of the mounting surface 20, i.e., a direction parallel to themounting surface 20, shall be hereinafter referred to simply as“in-plane direction”. The resin member 5 is a synthetic resin moldedarticle and made of a thermosetting or thermoplastic synthetic resinsuch as epoxy resin, polyamide resin, polyphenylene sulfide resin,polybutylene terephthalate resin, and the like. The electronic device 1is configured such that it carries the electronic component 3 on themounting surface 20 of the support member 2 via the conductive bondinglayer 4, with the resin member 5 covering the carried electroniccomponent 3 and the mounting surface 20.

The support member 2 has a main body 21 and a metallized layer 22. Themain body 21 is made of a metal material having good conductivity, suchas Cu, Fe, Ni, Pd, Pt, and Al, for example, or an alloy (e.g., 42 alloyand the like) containing at least one of these metal elements. Themetallized layer 22 is a metal thin film formed on the main body 21 andincludes the mounting surface 20. Namely, the mounting surface 20 isprovided as the surface of the metallized layer 22. In the presentembodiment, the metallized layer 22 is formed of a film of a metalmaterial mainly composed of at least one of Ni, Au, Pd, and Ag byplating or the like.

The mounting surface 20 is formed on part of one planar metal surface ofthe support member 2 by performing a laser beam irradiation treatmentfor enhancing the joint (i.e., bond) with the resin member 5. Morespecifically, the mounting surface 20 includes a placement surface 23and a sealing surface 24. The placement surface 23 is a surface of ametallic nature bonded to the conductive bonding layer 4 and located ina central part in the in-plane direction of the mounting surface 20. The“surface of a metallic nature” is a surface mainly composed of metal andincludes a metal surface, and a metal compound surface (e.g., metaloxide surface). In the present embodiment, the placement surface 23 isformed as a metal surface with a good wettability for the materialforming the conductive bonding layer 4.

As shown in FIG. 3, the placement surface 23 is formed to have a planarshape that is rectangular corresponding to the rectangular planar shapeof the electronic component 3. The sealing surface 24 is a surface of ametallic nature adjoining the placement surface 23 in the in-planedirection, and provided outside the placement surface 23 such as tosurround the placement surface 23. The resin member 5 covers theelectronic component 3, and is bonded to the sealing surface 24.

The sealing surface 24 includes a rough surface 25. The rough surface 25is formed by a plurality of laser irradiation marks 26 that aregenerally circular. The laser irradiation marks 26 are crater-likedepressions and protrusions with an outside diameter of 5 μm to 300 μm,and formed by irradiating the mounting surface 20 with a pulsed laserbeam. One laser irradiation mark 26 that is generally circularcorresponds to one emission of a pulsed laser beam.

As shown in FIG. 3, in the present embodiment, the rough surface 25 isformed in a rectangular shape as viewed in plan, with a predeterminedline width, more specifically a width corresponding to twice as large asthe outside diameter of a laser irradiation mark 26. Namely, there isformed a non-laser-irradiated region 27 without the laser irradiationmarks 26 on the inner side in the in-plane direction of the roughsurface 25 in the rectangular shape on the sealing surface 24. In thepresent embodiment, there is also formed a region that does not havelaser irradiation marks 26 on the outer side in the in-plane directionof the rough surface 25 on the sealing surface 24.

As noted above, the rough surface 25 is formed by irradiating the outerside in the in-plane direction of the non-laser-irradiated region 27that is located closer to the central part in the in-plane direction ofthe mounting surface 20 with a pulsed laser beam. Thisnon-laser-irradiated region 27 forms a major part of the placementsurface 23. More specifically, in the present embodiment, the placementsurface 23 generally overlaps with the non-laser-irradiated region 27.

The rough surface 25 includes a first region 291 and a second region292. A plurality of laser irradiation marks 26 are formed each in thefirst region 291 and second region 292. The second region 292 has ahigher density of laser irradiation marks 26 in the in-plane directionthan that of the first region 291. More specifically, in the presentembodiment, the second region 292 is formed by setting the laser beamirradiation density 1.25 times or more higher than that of the firstregion 291.

In the present embodiment, the second region 292 is providedcorrespondingly to portions of the joint between the support member 2and the conductive bonding layer 4 and resin member 5 where internalstress is higher than other parts. More specifically, the second region292 is provided in areas near four corners of the rectangular shape ofthe electronic component 3. Namely, the second region 292 is provided incorner parts of the planar shape of the rough surface 25 that isrectangular.

FIG. 4A shows a part of the IV-IV section of FIG. 3 corresponding to thefirst region 291. FIG. 4B shows a part of the IV-IV section of FIG. 3corresponding to the second region 292. As shown in FIG. 4A and FIG. 4B,a plurality of first protrusions 261 and a plurality of secondprotrusions 262 are formed in the rough surface 25.

The first protrusions 261 are protruded parts formed along an outer edgeof laser irradiation marks 26 in a crater shape and have a height of 0.5μm to 5 μm. The height of the first protrusion 261, the definition ofwhich will be given later, is indicated with an arrow H1 in FIG. 4A andFIG. 4B.

The second protrusions 262 are protruded parts formed inside the firstprotrusions 261 and around the first protrusions 261 and have a heightof 1 nm to 500 nm and a width of 1 nm to 300 nm. Namely, the secondprotrusions 262 are formed inside the laser irradiation marks 26 andaround the laser irradiation marks 26. The second protrusions 262 in thesecond region 292 are formed higher than the second protrusions 262 inthe first region 291. The height of the second protrusion 262, thedefinition of which will be given later, is indicated with an arrow H2in FIG. 4A and FIG. 4B.

The second protrusions 262 have a width of 1 nm to 300 nm. Thedefinition of the width of the second protrusions 262 will also be givenlater. The rough surface 25 is formed such that two adjacent secondprotrusions 262 are spaced apart by 1 nm to 300 nm.

As noted above, the second protrusions 262 have a height that issufficiently smaller than the height of the first protrusions 261.Therefore, the height of the first protrusions 261 can be definedwithout taking account of the height of the second protrusions 262.Namely, the height of the first protrusion 261 is the distance between ahighest position and a lowest position of a first protrusion 261 in adirection orthogonal to the in-plane direction, i.e., in the up and downdirection in FIG. 4A and FIG. 4B of an imaginary cross-sectional curve(see dotted line in FIG. 4A and FIG. 4B) of the first protrusion 261,with the second protrusions 262 smoothed out.

The height of the second protrusion 262 is the distance between ahighest position and a lowest position of a second protrusion 262 in adirection orthogonal to a horizontal line when the imaginarycross-sectional curve of the first protrusion 261 described above isextended to be horizontal. The width of the second protrusion 262 is thedistance between two adjacent lowest positions of second protrusions 262in a direction orthogonal to the direction in which the height of thesecond protrusions 262 is defined.

Manufacturing Method of the Structure of the First Embodiment

The electronic device 1 having the structure described above can beproduced as follows. Description of manufacturing processes of thedetailed features mentioned above that are commonly provided to theelectronic device 1 will be omitted.

First, part of one metal surface of the support member 2, i.e., regionsoutside the non-laser-irradiated region 27 in the in-plane direction isirradiated multiple times with a moving pulsed laser beam to form therough surface 25 that has multiple laser irradiation marks 26 that aregenerally circular. The conditions of the laser beam irradiation are asfollows. An Nd:YAG laser may be used, for example, as the laser lightsource. “Nd:YAG” is the acronym of “neodymium-doped yttrium aluminumgarnet”. With the Nd:YAG laser, a basic wavelength of 1064 μm, or aharmonic of 533 μm or 355 μm can be used. The spot diameter of theprojected laser beam is 5 μm to 300 μm. The energy density is 5 J/cm2 to100 J/cm2, and the pulse width, i.e., irradiation time per one spot, is10 ns to 1000 ns.

FIG. 5 shows one laser irradiation mark 26 that has just been formed byone emission of a laser beam. The broken line in the drawing representsthe laser beam. The laser beam irradiation induces melting and/orvaporization of the metal, as well as concurrent solidification and/ordeposition of the metal. As a result, first protrusions 261 of amicroscopic size are formed in a generally circular shape as viewed inplan, as shown in FIG. 5. The outside diameter of the first protrusion261 is slightly larger than the spot diameter of the projected laserbeam. Also, second protrusions 262 of a nanoscopic or submicroscopicsize are formed inside and around the first protrusions 261.

The conditions of the laser beam scanning are as follows. In the presentembodiment, an X-Y stage for removably supporting the laser lightsource, optical system, and support member 2 is fixedly installed suchthat it is not readily moved. The support member 2 is mounted on the X-Ystage. The laser light source is driven in sync with the driving of theX-Y stage such that the laser beam is projected to a desired position onthe mounting surface 20. This way, the laser beam can be moved in adesired pattern on the mounting surface 20. In the followingdescription, for ease of explanation, phrases that imply as though thelaser beam would move on the mounting surface 20 may be used.

In the present embodiment, as shown in FIG. 6, the laser beam is moved,starting from position P10, on the rectangular shape P11-P12-P13-P14.Thus, laser irradiation marks 26 are continuously formed on therectangular shape P11-P12-P13-P14. Position P10 is located at a pointdisplaced from position P14 on the side P14-P11 in the positivedirection of X-axis in the drawing by about ½ of the spot diameter ofthe projected laser beam.

More specifically, first, the support member 2 is moved in the negativedirection of X-axis in the drawing so that the mounting surface 20 isscanned by the laser beam straight from position P10 to position P11 inthe positive direction of X-axis in the drawing. Next, the supportmember 2 is moved in the positive direction of Y-axis in the drawing sothat the mounting surface 20 is scanned by the laser beam straight fromposition P11 to position P12 in the negative direction of Y-axis in thedrawing. Successively, the support member 2 is moved in the positivedirection of X-axis in the drawing so that the mounting surface 20 isscanned by the laser beam straight from position P12 to position P13 inthe negative direction of X-axis in the drawing. Further, the supportmember 2 is moved in the negative direction of Y-axis in the drawing sothat the mounting surface 20 is scanned by the laser beam straight fromposition P13 to position P14 in the positive direction of Y-axis in thedrawing.

After that, the laser beam is moved, starting from position P20, on therectangular shape P21-P22-P23-P24. Thus, laser irradiation marks 26 aresuccessively formed on the rectangular shape P21-P22-P23-P24. Therectangular shape P21-P22-P23-P24 is positioned outside the rectangularshape P11-P12-P13-P14 by one laser beam spot. The side P21-P22 isadjacent to the side P11-P12, the side P22-P23 is adjacent to the sideP12-P13, the side P23-P24 is adjacent to the side P13-P14, and the sideP24-P21 is adjacent to the side P14-P11. Position P20 is located at apoint displaced from position P24 on the side P24-P21 in the positivedirection of X-axis in the drawing by about ½ of the spot diameter ofthe projected laser beam.

More specifically, first, the laser beam is moved straight from positionP20 to position P21 in the positive direction of X-axis in the drawing.Next, the laser beam is moved straight from position P21 to position P22in the negative direction of Y-axis in the drawing. Successively, thelaser beam is moved straight from position P22 to position P23 in thenegative direction of X-axis in the drawing. Further, the laser beam ismoved straight from position P23 to position P24 in the positivedirection of Y-axis in the drawing.

The speed of moving the laser beam, starting from position P10 andreaching P14 via P11, P12, and P13, is not constant. More specifically,the support member 2 is stopped before the projection of laser beam atposition P10. The movement of the support member 2 in the negativedirection of X-axis in the drawing is started with or immediately beforethe projection of laser beam at position P10. After that, the supportmember 2 is continuously moved until the projected laser beam pointreaches position P11.

For a predetermined acceleration time after the support member 2 isstarted to move, the moving speed of the support member 2 is increased,after which the moving speed is made constant. After that, the movingspeed of the support member 2 is decreased, and the movement of thesupport member 2 in the negative direction of X-axis in the drawing isstopped with or immediately after the projection of laser beam atposition P11 for changing the moving direction of the support member 2.Therefore, the scanning speed becomes relatively slow near position P10immediately after the start of scanning, and near position P11immediately before the end of scanning. Accordingly, the density of thelaser irradiation marks 26 is relatively high near position P10 and nearposition P11. In comparison, the scanning speed is relatively higharound an intermediate position between P10 and P11, as a result ofwhich the density of the laser irradiation marks 26 is relatively lowthere.

At position P11, the moving direction of the support member 2 ischanged. Namely, the support member 2 travels in the positive directionof Y-axis in the drawing for the laser beam to move from position P11 toP12. Once the support member 2 starts moving in the positive directionof Y-axis in the drawing, the support member 2 continuously moves untilthe projected laser beam point reaches position P12. As with thescanning between positions P10-P11 described above, the scanning speedbecomes relatively slow near position P11 immediately after the start ofscanning, and near position P12 immediately before the end of scanning.Accordingly, the density of the laser irradiation marks 26 is relativelyhigh near position P11 and near position P12. In comparison, thescanning speed is relatively high in the intermediate position betweenP11 and P12, as a result of which the density of the laser irradiationmarks 26 is relatively low there.

The same applies to the movement of the laser beam from position P12 toP13, and the movement from position P13 to P14. Thus, the density of thelaser irradiation marks 26 becomes relatively high at the corners of therectangular shape P11-P12-P13-P14. In comparison, the density of thelaser irradiation marks 26 becomes relatively low around intermediatepositions on each side of the rectangular shape P11-P12-P13-P14.

The scanning with the laser beam starting from position P20 and reachingP24 via P21, P22, and P23 is carried out similarly to the scanning withthe laser beam described above starting from position P10 and reachingP14 via P11, P12, and P13. Thus, the density of the laser irradiationmarks 26 becomes relatively high at the corners of the rectangular shapeP21-P22-P23-P24. In comparison, the density of the laser irradiationmarks 26 becomes relatively low around intermediate positions on eachside of the rectangular shape P21-P22-P23-P24, In this way, secondregions 292 having a higher density of laser irradiation marks 26 in thein-plane direction than that of first regions 291 are formed at thecorners of the rectangular planar shape of the rough surface 25.

In the second regions 292 having a higher density of laser irradiationmarks 26 than that of the first regions 291, the amount of vaporizationand deposition of metal caused by laser beam irradiation is relativelyhigh. Therefore, the second protrusions 262 in the second region 292 areformed higher than the second protrusions 262 in the first region 291.

After the rough surface 25 is formed on the mounting surface 20 by laserbeam irradiation as described above, the conductive bonding layer 4 isjoined to the placement surface 23 including the non-laser-irradiatedregion 27. Successively, the electronic component 3 is joined to theconductive bonding layer 4 on the opposite side from the side joined tothe mounting surface 20. Thus, the electronic component 3 is mounted onthe support member 2 via the conductive bonding layer 4.

After that, the resin member 5, which is a synthetic resin moldedarticle, is joined to the sealing surface 24, whereby the resin member 5covers the electronic component 3. At this time, the rough surface 25has been formed on the sealing surface 24. The rough surface 25includes, when viewed microscopically, first protrusions 261 of amicroscopic size and second protrusions 262 of a nanoscopic orsubmicroscopic size, as shown in FIG. 4A and FIG. 4B. Therefore, thesupport member 2 and the resin member 5 form a favorable bond with eachother.

(Effects of First Embodiment)

As described above, in the present embodiment, the support member 2 isirradiated with a laser beam to form the rough surface 25 of multiplelaser irradiation marks 26 on the sealing surface 24 of the supportmember 2. The rough surface 25, provided for enhancing the joint (bond)with the resin member 5, includes first regions 291, and second regions292 having a higher density of laser irradiation marks 26 in thein-plane direction than that of the first regions 291.

The second regions 292 having a high density of laser irradiation marks26 can be provided to desired areas as required. More specifically, thesecond regions 292 having a high density of laser irradiation marks 26are provided, for example, in areas near four corners of the rectangularshape of the electronic component 3, which are portions of the jointbetween the support member 2 and the conductive bonding layer 4 andresin member 5 where internal stress is high. Therefore, the possibilityof failures such as peeling of the resin member 5 and the like resultingfrom internal stress is reduced as much as possible. This means that thebond between the sealing surface 24 that is the surface of a metallicnature of the support member 2 and the resin member 5 is enhanced evenmore.

In the second regions 292 having a high density of laser irradiationmarks 26, the second protrusions 262 are formed higher than those in thefirst regions 291 having a low density of laser irradiation marks 26.Accordingly, the bond with the resin member 5 is improved even more inportions where internal stress is high.

In the present embodiment, the second regions 292 having a high densityof laser irradiation marks 26 are not provided to the entire roughsurface 25 but only to necessary parts. More specifically, the secondregion 292 is selectively formed near a starting point and near an endpoint of a unidirectional travel of the laser beam on the mountingsurface 20. According to the present embodiment, a favorable bond can besecured while an increase in processing time is minimized.

Structure of Second Embodiment

The structure of an electronic device 1 of the present embodiment willbe described with reference to FIG. 11 to FIG. 14. As shown in FIG. 11,the electronic device 1 includes a support member 2, an electroniccomponent 3, a conductive bonding layer 4, and a resin member 5.

The support member 2 has a main body 21 and a metallized layer 22. Inthe present embodiment, the metallized layer 22 is made of a film of ametal material (e.g., nickel-based metal) with a good wettability forthe material forming the conductive bonding layer 4, formed by platingor the like.

A mounting surface 20 is formed on part of one planar metal surface ofthe support member 2 by performing a laser beam irradiation treatmentfor enhancing the joint (i.e., bond) with the conductive bonding layer 4and resin member 5. More specifically, the mounting surface 20 includesa placement surface 23 and a sealing surface 24. Namely, the metallizedlayer 22 includes the placement surface 23 and sealing surface 24.

The sealing surface 24 includes a rough surface 25. The rough surface 25is formed by a plurality of laser irradiation marks 26 that aregenerally circular. The laser beam for forming the rough surface 25 maybe referred to as “surface roughening beam” below.

The placement surface 23 includes a boundary area 231. The boundary area231 is irradiated with a post-processing beam that is a laser beam witha lower energy level than that of the surface roughening beam. In thisway, the boundary area 231 is formed for an improved wettability for thematerial forming the conductive bonding layer 4 than that of the roughsurface 25 of the sealing surface 24. The boundary area 231 is aband-like portion in a generally rectangular shape when viewed in planadjoining the sealing surface 24 in the in-plane direction of theplacement surface 23. More specifically, the boundary area 231 isprovided on an outer edge of the non-laser-irradiated region 27. In thisway, the placement surface 23 is formed as a surface of a metallicnature with a good wettability for the material forming the conductivebonding layer 4 as a whole.

FIG. 14 shows a portion of the XIV-XIV section of FIG. 13. As shown inFIG. 14, a plurality of first protrusions 261 and a plurality of secondprotrusions 262 are formed on the rough surface 25.

(Manufacturing Method and Effects)

The electronic device 1 having the structure described above can beproduced as follows. Description of manufacturing processes of thedetailed features mentioned above that are commonly provided to theelectronic device 1 will be omitted.

First, part of one metal surface of the support member 2, i.e., regionson the outer side in the in-plane direction of the non-laser-irradiatedregion 27 is irradiated multiple times with a moving pulsed surfaceroughening beam to form the rough surface 25 that has multiple laserirradiation marks 26 that are generally circular. The conditions of thesurface roughening beam irradiation are as follows. An Nd:YAG laser maybe used, for example, as the laser light source. With the Nd:YAG laser,a basic wavelength of 1064 μm, or a harmonic of 533 μm or 355 μm can beused. The projected beam spot has a diameter of 5 μm to 300 μm. Theenergy density is 5 J/cm2 to 100 J/cm2, and the pulse width, i.e.,irradiation time per one spot, is 10 ns to 1000 ns.

FIG. 15 shows one laser irradiation mark 26 that has just been formed byprojection of one spot of the surface roughening beam. The broken linein the drawing represents the surface roughening beam. The projection ofthe surface roughening beam induces melting and/or vaporization of themetal, as well as concurrent solidification and/or deposition of themetal. As a result, first protrusions 261 of a microscopic size areformed in a generally circular shape as viewed in plan, as shown in FIG.15. The outside diameter of the first protrusion 261 is slightly largerthan the spot diameter of the projected surface roughening beam. Also,second protrusions 262 of a nanoscopic or submicroscopic size are formedinside and around the first protrusions 261.

The scanning with the surface roughening beam and the post-processingbeam to be described later is performed as follows. In the presentembodiment, an X-Y stage for removably supporting the laser lightsource, optical system, and support member 2 is fixedly installed suchthat it is not readily moved. The support member 2 is mounted on the X-Ystage. The laser light source is driven in sync with the driving of theX-Y stage such that the laser beam is projected to a desired position onthe mounting surface 20. This way, the laser beam can be moved in adesired pattern on the mounting surface 20. In the followingdescription, for ease of explanation, phrases that imply as though thelaser beam would move on the mounting surface 20 may be used.

FIG. 16 shows how a plurality of laser irradiation marks 26 aresuccessively formed by the surface roughening beam travelling toward theleft in the drawing. For simplification of illustration and description,second protrusions 262 (see FIG. 15) in the rough surface 25 are notshown in FIG. 16.

As shown in FIG. 16, the support member 2 is irradiated and scanned withthe surface roughening beam to form the rough surface 25 of a pluralityof laser irradiation marks 26 on the sealing surface 24 of the supportmember 2. A non-laser-irradiated region 27 is formed closer to a centralpart in the in-plane direction of the support member 2. Namely, thesealing surface 24 is formed on the outer side in the in-plane directionof the non-laser-irradiated region 27.

When the plurality of laser irradiation marks 26 are formed byprojection of the surface roughening beam, deposits 263 accumulateinside and around each of the laser irradiation marks 26. The deposits263 are composed of the metal that forms the metallized layer 22,compounds and the like (i.e., typically oxides) of the metal.Accumulation and the like of these deposits 263 create minuteirregularities inside and around the laser irradiation marks 26. Namely,the deposits 263 are one factor that causes formation of the secondprotrusions 262 shown in FIG. 15.

Accumulation of deposits 263 and concurrent formation of minuteirregularities may also occur in the boundary area 231 that adjoins thesealing surface 24 in the in-plane direction of the placement surface23. If this is the case, there is a risk that wettability of thematerial forming the conductive bonding layer 4 may be deteriorated inthe boundary area 231 due to the influence of the compounds and the likementioned above. If plating of a nickel-based metal that has a goodwettability for solder is used as the metallized layer 22, inparticular, deposits 263 that are nickel oxides largely deteriorates thewettability for solder. Providing a margin area with a predeterminedwidth between the placement surface 23 and the rough surface 25 inconsideration of such wettability deterioration in the boundary area 231leads to an increase in size of the electronic device 1.

Internal stresses such as heat stress can readily arise near cornerparts of the planar shape of the electronic component 3 that isrectangular. In this respect, the deteriorated wettability in theboundary area 231 and/or formation of a margin area as noted above mayweaken the bond between the support member 2 and the conductive bondinglayer 4 and resin member 5 near the corner parts of the electroniccomponent 3. There is thus a risk of peeling and/or crack formationoccurring in the conductive bonding layer 4 near the corner parts of theelectronic component 3.

In the present embodiment, as shown in FIG. 17, the boundary area 231 isirradiated with a post-processing beam. Post-processing beam irradiationis carried out using the same laser irradiation equipment as that forthe surface roughening beam irradiation, after the surface rougheningbeam irradiation is finished. The laser irradiation equipment includes alaser light source, an optical system, an X-Y stage, and a controller orthe like for these components. Therefore, once the support member 2 ismounted on the X-Y stage, the support member 2 is not removed from theX-Y stage until irradiation with the surface roughening beam andirradiation with the post-processing beam thereafter are completed.

The conditions of the post-processing beam irradiation are as follows.The same parameters as those of the surface roughening beam may be usedfor the wavelength, projected beam spot diameter, and pulse width of thepost-processing beam. The energy density is 0.5 J/cm² to 3 J/cm². Toimprove the wettability even more, the irradiation pitch, i.e., thedistance between centers of two successive spots, is set shorter thanthat of the surface roughening beam. More specifically, when the spotdiameter and the irradiation pitch of the surface roughening beam areset 80 μm and 70 μm, respectively, the spot diameter and the irradiationpitch of the post-processing beam may be set 80 μm and not more than 35μm, respectively.

Irradiation with the post-processing beam favorably removes thecompounds and the like mentioned above, which are one cause ofdeterioration of wettability for the material forming the conductivebonding layer 4, from the boundary area 231, as shown in FIG. 18. Thus,the wettability for the material forming the conductive bonding layer 4is made improved in the boundary area 231 than on the rough surface 25of the sealing surface 24.

In this way, the boundary area 231 is irradiated with thepost-processing beam after the rough surface 25 has been formed on themounting surface 20 by projection of the surface roughening beam. Thus,the placement surface 23, which is a surface of a metallic nature joinedto the conductive bonding layer 4 and includes the boundary area 231 andthe non-laser-irradiated region 27, is formed on the support member 2.Projection of the surface roughening beam and projection of thepost-processing beam thereafter are carried out continuously using thesame laser irradiation equipment without performing removal andattachment operations of the support member 2 in between. Therefore, theplacement surface 23 having a favorable wettability for the materialforming the conductive bonding layer 4 can be formed swiftly with a goodpositional precision.

After that, the conductive bonding layer 4 is formed on the placementsurface 23 by coating or the like, as shown in FIG. 19. Successively, asshown in FIG. 20, the electronic component 3 is joined to the conductivebonding layer 4 on the opposite side from the side joined to themounting surface 20. Thus, the electronic component 3 is mounted on thesupport member 2 via the conductive bonding layer 4.

As described above, the wettability for the material forming theconductive bonding layer 4 is made improved in the boundary area 231 onthe placement surface 23 than on the rough surface 25 of the sealingsurface 24. Therefore, the bond with the conductive bonding layer 4 onthe placement surface 23 can be secured favorably.

After that, as shown in FIG. 21, the resin member 5, which is asynthetic resin molded article, is joined to the sealing surface 24 tocover the electronic component 3 with the resin member 5, and thus theelectronic device 1 is produced. At this time, the rough surface 25 hasbeen formed on the sealing surface 24. The rough surface 25 includes,when viewed microscopically, first protrusions 261 of a microscopic sizeand second protrusions 262 of a nanoscopic or submicroscopic size, asshown in FIG. 14. Therefore, the support member 2 and the resin member 5form a favorable bond with each other by the anchoring effect.

As described above, in the present embodiment, a good bond with theconductive bonding layer 4 on the placement surface 23 is secured, whilea favorable bond is also realized between the sealing surface 24 and theresin member 5.

(Variation Examples)

The present disclosure is not limited to the embodiments describedabove. The following changes can be made as required to the embodimentsdescribed above. Typical variation examples will now be described below.In the following description of variation examples, only the featuresdifferent from those of the embodiments described above will beexplained. Therefore, descriptions of previous embodiments can bereferred to as required with respect to constituent elements given thesame reference numerals as those of the embodiments described above inthe following description of variation examples, unless there aretechnical contradictions or otherwise additionally described.

The support member 2 is not limited to a lead frame. The support member2 may be a so-called SOI substrate, for example. SOI is the acronym of“Silicon on Insulator”. The support member 2 need not necessarilyinclude the metallized layer 22 if the main body 21 is made of a metalmaterial and its surface can form a reasonably good bond with theconductive bonding layer 4 and the resin member 5.

The electronic component 3 is not limited to an IC chip. For example,the electronic component 3 may be a capacitor device or the like.

Parts of the sealing surface 24 that are not provided with the roughsurface 25 need not necessarily be covered by the resin member 5.Alternatively, the rough surface 25, or the plurality of laserirradiation marks 26, may be formed on the entire sealing surface 24(see FIG. 7 to FIG. 9). Parts of the rough surface 25, i.e., an outeredge in the in-plane direction, need not necessarily be covered by theresin member 5.

As shown in FIG. 7, the second region 292 may be provided in areas neareach side of the rectangular shape of the electronic component 3. Thestructure of the laser irradiation marks 26 in the example shown in FIG.7 is the same as those of the embodiments described above (see FIG. 4Aand FIG. 46).

The laser is not limited to the type used in the embodiments describedabove. For example, CO2 gas laser, excimer laser, and the like can beused.

The laser scanning method is not limited to the type used in theembodiments described above. Namely, for example, the support member 2may be fixed, and the laser beam spot can be moved on the mountingsurface 20, using an optical system.

There is no particular limitation to the laser beam moving directions.Namely, for example, as shown in FIG. 6, the laser beam can be movedalong a closed curve. Alternatively, for example, as indicated by solidline arrows in FIG. 8, the laser beam can be reciprocated many times.More specifically, when the scanning is carried out in the manner shownin FIG. 8, the laser beam is not emitted during the relative movement ofthe support member 2 in the subscanning direction (see the broken linearrows in FIG. 8). The support member 2 is irradiated with the laserbeam during the relative movement in the main scanning direction (seethe solid line arrows in FIG. 8) that is performed between one run ofscanning in the subscanning direction and a subsequent run of scanningin the subscanning direction. The direction of relative movement of thesupport member 2 in one run of scanning in the main scanning directionis opposite from that of a subsequent run of scanning in the mainscanning direction.

As shown in FIG. 9, when the rough surface 25 is formed on the entiresealing surface 24, the second region 292 having a higher density oflaser irradiation marks 26 may be provided correspondingly to portionsof the joint between the support member 2 and the conductive bondinglayer 4 and resin member 5 where internal stress is higher than otherparts. Namely, the second region 292 may be formed in a band-like shapeincluding areas near the four corners of the rectangular shape of theelectronic component 3 and extending from these areas along one side(i.e., upper side in FIG. 9) of the outer shape that is rectangular whenviewed in plan of the electronic component 3. The structure of the laserirradiation marks 26 in the example shown in FIG. 9 is also the same asthose of the embodiments described above (see FIG. 4A and FIG. 4B).

When the scanning is carried out in the manner shown in FIG. 9,similarly, the laser beam is not emitted during the relative movement ofthe support member 2 in the subscanning direction (see the broken linearrows in FIG. 9). The support member 2 is irradiated with the laserbeam during the relative movement in the main scanning direction (seethe solid line arrows in FIG. 9) that is performed between one run ofscanning in the subscanning direction and a subsequent run of scanningin the subscanning direction. The direction of relative movement of thesupport member 2 in one run of scanning in the main scanning directionis opposite from that of a subsequent run of scanning in the mainscanning direction.

The second protrusions 262 need only be formed inside the firstprotrusions 261 or around the first protrusions 261.

The method of forming the second regions 292 having a higher density oflaser irradiation marks 26 is not limited to the specific examples inthe embodiments described above. Namely, the present disclosure is notlimited to the methods described in the embodiments in which the densityof the laser irradiation marks 26 is varied using changes in the speedof relative movements between the support member 2 and the opticalsystem. More specifically, for example, the speed of the relativemovement between the support member 2 and the optical system can be madeconstant while the laser beam spot passes through a region correspondingto the rough surface 25 on the mounting surface 20. In this case, thedensity of the laser irradiation marks 26 can be varied by adjusting theoscillation frequencies of the laser beam. Alternatively, the density ofthe laser irradiation marks 26 can be varied by controlling both thespeed of relative movements between the support member 2 and the opticalsystem, and the oscillation frequencies of the laser beam.

The manner in which the laser irradiation marks 26 are formed in thefirst regions 291 and second regions 292 is not limited to the specificexamples in the embodiments described above. For example, some parts ofthe first region 291 may not have the laser irradiation marks 26. Thedensity of the laser irradiation marks 26 formed in the second region292 may be constant, or, the second region 292 may have specific areaswhere the formation density is particularly high.

As shown in FIG. 10, the rough surface 25 may be provided only in areascorresponding to portions of the joint between the support member 2 andthe conductive bonding layer 4 and resin member 5 where internal stressis higher than other parts. More specifically, the rough surface 25 maybe provided in areas near four corners of the rectangular shape of theelectronic component 3. The structure of the laser irradiation marks 26in the example shown in FIG. 10 is also the same as those of theembodiments described above (see FIG. 4A and FIG. 4B). The same effectsas those of the embodiments described above can be achieved with thisstructure, too.

The formation of the conductive bonding layer 4 on the placement surface23 shown in FIG. 19 and the placement of the electronic component 3 onthe placement surface 23 shown in FIG. 20 can be carried outsimultaneously.

The irradiation conditions, i.e., wavelengths, projected beam spotdiameters, pulse widths, and so on, of the surface roughening beam andthe post-processing beam may be different from each other. For example,the wavelength of the post-processing beam can be set to a shortwavelength (i.e., ultraviolet wavelength, for example) from theviewpoint of oxide removal. More specifically, a basic wavelength of1064 μm can be used for the surface roughening beam, and a thirdharmonic of 355 μm can be used for the post-processing beam, when usingthe Nd:YAG laser. In this case, projection of the post-processing beamhaving an ultraviolet wavelength removes the oxide or the like byablation that does not involve a thermal process. Thus, removal ofoxides and the like is made possible with minimum thermal effects to thesurrounding area. The post-processing beam may be emitted continuouslyinstead of being emitted in pulses.

Different types of laser may be used for the surface roughening beam andthe post-processing beam. For example, a long-wavelength laser can beused suitably for the surface roughening beam, whereby melting of metalreadily occurs due to a thermal process. On the other hand, ashort-wavelength laser such as excimer laser can be used suitably forthe post-processing beam, for removal of oxides or the like with minimumthermal effects to the surrounding area as mentioned above.

The support member 2 may be removed and attached between the irradiationwith the surface roughening beam and the irradiation with thepost-processing beam.

As shown in FIG. 22, the post-processing beam can be projected also tothe laser irradiation marks 26 adjoining the non-laser-irradiated region27 in the in-plane direction in addition to the outer edge of thenon-laser-irradiated region 27. In this case, as shown in FIG. 23, theboundary area 231 includes the outer edge of the non-laser-irradiatedregion 27 (i.e., inner edges of the rough surface 25), and some parts ofthe plurality of laser irradiation marks 26 adjoining the outer edge inthe in-plane direction and arrayed in a rectangular shape when viewed inplan.

This will cause the conductive bonding layer 4 to make tight contactwith parts of laser irradiation marks 26 included in the boundary area231, as shown in FIG. 24. With this structure, an outer edge of theconductive bonding layer 4 form a favorable firm bond with the placementsurface 23 because of the irregularities provided by the laserirradiation marks 26. Therefore, with this structure, the bond with theconductive bonding layer 4 on the placement surface 23 can be securedeven more favorably.

The outer shape in a plan view of the placement surface 23 is notlimited to the rectangular shape such as the one shown in FIG. 13.Considering the internal stress, however, it is preferable for thematerial forming the conductive bonding layer 4 to have a goodwettability at positions corresponding to corner parts of the electroniccomponent 3, as mentioned above. Therefore, the placement surface 23 ispreferably irradiated with the post-processing beam at least inpositions corresponding to corner parts of the electronic component 3.Namely, the placement surface 23 having a good wettability for thematerial forming the conductive bonding layer 4 can be formed such thatsquare parts of the corners protrude outward in the in-plane directionin a plan view.

In the example shown in FIG. 25, for example, the placement surface 23has a planar shape, with four margin areas 281 being eliminated from thenon-laser-irradiated region 27 that is rectangular. A boundary area 231is provided to each of four corners of the non-laser-irradiated region27 that is rectangular. The margin area 281 is formed in a trapezoidalshape, the lower base being positioned outside relative to the upperbase. The margin area 281 is positioned such that its lower basecontacts each side of the non-laser-irradiated region 27 that isrectangular. Namely, the margin area 281 is provided between twoboundary areas 231 adjoining in the up and down direction or in the leftto right direction in the drawing. In other words, the placement surface23 is formed as a region where a rectangular area inside thenon-laser-irradiated region 27 and four boundary areas 231 that aregenerally rectangular and protrude respectively from four corners ofthis rectangular area overlapping one upon another.

In the margin area 281 provided between the placement surface 23 and therough surface 25, the wettability for the material forming theconductive bonding layer 4 may be deteriorated. In such a structure,however, the margin area 281 is not provided to positions correspondingto corner parts of the electronic component 3. Namely, the boundaryareas 231 at positions corresponding to the corner parts of theelectronic component 3 are formed with a good wettability for thematerial forming the conductive bonding layer 4. Meanwhile, corners ininner edges of the rough surface 25 adjoining the outside of theboundary areas 231 in the in-plane direction form a favorable bond withthe resin member 5. Therefore, with this structure, peeling and/orcracks of the conductive bonding layer 4 can favorably be prevented fromoccurring near corner parts of the electronic component 3.

Even if the placement surface 23 is rectangular, margin areas 281 can beprovided at positions other than corners. For example, in the exampleshown in FIG. 26, corners in the inner edges (i.e., inner corners) ofthe rough surface 25 formed in a frame shape as viewed in plan have afan shape protruding toward the placement surface 23. Namely, the innercorners of the rough surface 25 include fan-shaped parts protrudingtoward a central part in the in-plane direction of the placement surface23. Boundary areas 231 are formed by irradiating some parts of thesefan-shaped areas (i.e., distal end portions in the protruding direction)with the post-processing beam. In such a structure, too, the margin area281 is not provided at positions corresponding to corner parts of theelectronic component 3. Accordingly, peeling and/or cracks of theconductive bonding layer 4 can favorably be prevented from occurringnear corner parts of the electronic component 3.

As shown in FIG. 27, the rough surface 25 may include a first region 291and a second region 292. A plurality of laser irradiation marks 26 areformed each in the first region 291 and second region 292. The secondregion 292 has a higher density of laser irradiation marks 26 in thein-plane direction than that of the first region 291. More specifically,in the present variation example, the second region 292 is formed bysetting the laser beam irradiation density 1.25 times or more higherthan that of the first region 291.

In the present variation example, the second region 292 is providedcorrespondingly to portions of the joint between the support member 2and the conductive bonding layer 4 and resin member 5 where internalstress is higher than other parts. More specifically, the second region292 is provided in areas near corner parts of the electronic component3. Namely, the second region 292 is provided in corner parts of theplanar shape of the rough surface 25 that is rectangular.

In the second regions 292 having a higher density of laser irradiationmarks 26 than that of the first regions 291, the amount of vaporizationand deposition of metal caused by laser beam irradiation is relativelyhigh. Therefore, the second protrusions 262 in the second region 292 areformed higher than the second protrusions 262 in the first region 291.This means that the bond between the support member 2 and the resinmember 5 is enhanced even more near corner parts of the electroniccomponent 3.

Meanwhile, there is a risk that wettability for the material forming theconductive bonding layer 4 may be deteriorated as mentioned above in theboundary areas 231 that form an outer edge of the placement surface 23.The risk is high particularly at positions near the second regions 292having a high density of laser irradiation marks 26. In the presentvariation example, however, the boundary areas 231 are also irradiatedwith the post-processing beam. Therefore, even though the second regions292 having a high density of laser irradiation marks 26 are provided inareas near the corner parts of the electronic component 3, thewettability for the material forming the conductive bonding layer 4 isfavorable in parts of the boundary areas 231 positioned correspondinglyto the corners of the electronic component 3. Therefore, with thisstructure, a good bond with the conductive bonding layer 4 on theplacement surface 23 is secured, while a favorable bond is also realizedbetween the sealing surface 24 and the resin member 5. Also, thepossibility of failures such as peeling and/or cracks of the conductivebonding layer 4 resulting from internal stress, or peeling and the likeof the resin member 5, are reduced as much as possible.

In the present variation example, the second regions 292 having a highdensity of laser irradiation marks 26 are not provided to the entirerough surface 25 but only to necessary parts. More specifically, thesecond region 292 is selectively formed near a starting point and nearan end point of a unidirectional travel of the laser beam on themounting surface 20. According to the present variation example, afavorable bond can be secured while an increase in processing time isminimized.

The manner in which the laser irradiation marks 26 are formed in thefirst regions 291 and second regions 292 is not limited to the specificexamples described above. For example, some parts of the first region291 may not have the laser irradiation marks 26. The density of thelaser irradiation marks 26 formed in the second region 292 may beconstant, or, the second region 292 may have specific areas where theformation density is particularly high.

As shown in FIG. 28, the rough surface 25 may be provided only atpositions corresponding to portions of the joint between the supportmember 2 and the conductive bonding layer 4 and resin member 5 whereinternal stress is higher than other parts. More specifically, the roughsurface 25 may be provided in areas near corner parts of the electroniccomponent 3. The structure of the laser irradiation marks 26 in theexample shown in FIG. 28 is also the same as those of the embodimentsdescribed above (see FIG. 14 and FIG. 15).

Variation examples are not limited to the examples illustrated above.Namely, various variation examples can be combined with each other.Also, various embodiments can be combined with each other. Moreover, allor some of the variation examples described above can be combined withcombinations of various embodiments as required.

The invention claimed is:
 1. An electronic device in which an electroniccomponent is mounted through a conductive bonding layer, the electronicdevice comprising: a support member that includes a metallic placementsurface joined to the conductive bonding layer, and a metallic sealingsurface provided on an outer side of the placement surface in anin-plane direction of the placement surface to adjoin the placementsurface and to surround the placement surface; and a resin member, whichis a synthetic resin molded article, joined to the sealing surface andcovering the electronic component, wherein: the sealing surface includesa rough surface having a plurality of laser irradiation marks having asubstantially circular shape; the rough surface includes a first regionand a second region, the second region having a higher density of thelaser irradiation marks in the in-plane direction than the first region;the rough surface includes a plurality of first protrusions providedcorrespondingly to the laser irradiation marks and having a height of0.5 μm to 5 μm, and a plurality of second protrusions provided insidethe first protrusions and/or around the first protrusions, and having aheight of 1 nm to 500 nm and a width of 1 nm to 300 nm; the secondprotrusions in the second region are taller than the second protrusionsin the first region.
 2. The electronic device according to claim 1,wherein: the second region is provided correspondingly to a portion of ajoint between the support member and the conductive bonding layer orbetween the support member and the resin member; and internal stress ishigher at the portion of the joint with the second region than in otherportions of the joint.
 3. The electronic device according to claim 1,wherein: the electronic component has a rectangular shape as a planarshape; and the second region is provided in portions near four cornersof the rectangular shape of the electronic component.
 4. The electronicdevice according to claim 3, wherein the second region is provided at aportion near each side of the rectangular shape of the electroniccomponent.
 5. The electronic device according to claim 1, wherein therough surface is provided such that two adjacent second protrusions arespaced apart by 1 nm to 300 nm.
 6. The electronic device according toclaim 1, wherein the second protrusions in the second region are tallerthan the second protrusions in the first region.